All-Optical Signal Modulation

Summary

 

The large bandwidth obtained using optical signals has led to the transmission and reception of vast amounts of information. Recent technologies have achieved a 1Tbps bandwidth thanks to photonic integrated circuits (PIC). This bandwidth is being further increased, as required by several new applications (Business analytics, Telemedicine, Content sharing, etc). Current PICs in the market can only multiplex, transmit, receive and demultiplex optical signals.

Researchers from King's College London have invented a novel optical modulation technology based on the high and ultrafast nonlinear optical properties of plasmonic metamaterials. This type of all-optical modulation allows the possibility of performing all-optical switching at 1Tbps rate.

This technology enables the possibility to develop an all-optical chip capable of performing processing functions in PICs on Tbps optical signals, such as signal compression (increasing the amount of bits transmitted without increasing the bit/rate), arithmetic functions (at a 1Tbps rate, 3 orders of magnitude faster than latest computers) and in general any kind of processing function required.

 

Technology

 

Researchers from King's College London have invented a portfolio of optical technologies to manipulate optical signals at the nanoscale including optical modulation using Plasmonic Metamaterials. Plasmonic metamaterials provide a unique platform for the design of low-energy consuming, ultrafast all-optical modulators integrated at the nanoscale as they have designed optical functionalities not found in nature.

 

The researchers have proposed two optical modulator designs as outlined below - Hyperbolic metamaterial-based optical modulator and ENZ (epsilon near zero) cavity based optical modulator. These can be used with silicon-photonics, the standard platform for the construction of Photonic Integrated Circuits.

 

The developed modulators work as the basis platform of an all-optical chip. This chip can be used between the typical receiver and transmitter PICs which are already commercially available to perform operations (or any kind of processing) on the optical signal.

 

1) Hyperbolic metamaterial based optical Modulator

This invention takes advantage of the hybrid hyperbolic mode created in the modulator structure shown in the figure below. This hybrid mode in the OFF state (without pump or optical excitation) has low coupling to the mode within the waveguide thus reducing the overall transmission of the device. In the ON state (with pump) the coupling is high and the transmission is increased.

Advantages:

  • Energy required for 30% modulation depth: 3.7pJ/bit.
  • Insertion losses in the ON state: 2.21dBs
  • High integrability with a footprint of: 300x440x600nm3
  • Designed to be compatible with silicon photonics and telecom applications (λ=1200-1800nm)

 

2) ENZ cavity based optical Modulator

This invention is based on the high optical nonlinearity and high reflectivity inherent of an ENZ (epsilon near zero) metamaterial. Please see figure below. This allows for a highly integrated optically controlled resonant cavity to be designed that can act as a filter, modulator, or even a sensor.

Advantages:

  • Energy required for 30% modulation depth: 600fJ/bit.
  • Insertion losses in the ON state: 0.9dBs
  • High integrability with a footprint of: 300x340x180nm3
  • Designed to be compatible with silicon photonics and telecom applications (λ =1200-1800nm)

 

Market Opportunity

 

The market segments directly related is the photonic integrated circuit (PIC) market. PIC market is expected to grow up to $1,547.6 millions in the coming years.

 

Commercial Opportunity

 

Industry partners are sought for commercial development of the technology.

 

Patent Information:
Category(s):
Physical Sciences
For Information, Contact:
Mugdha Joshi
IP & Licensing Manager
King's College London
mugdha.joshi@kcl.ac.uk
Inventors:
Gregory Wurtz
Anatoly Zayats
Cillian McPolin
Keywords: